Dear Nathan Plant-Povey,
Hello! Welcome to the Microsoft Community. I'm glad to be able to assist you. If I misunderstand your question, please let me know promptly.
Knowing that you have encountered some problems when using McAffee, it will actively help you download, expand and modify your browser home page.
I understand your annoyance at this problem, but the current situation may be frustrating.
In fact, like you, we are all members of the Microsoft community. Microsoft community is an open platform, where we help users solve Windows-related problems, but we can't investigate or pursue anything about McAffee.
At the same time, McAffee is not a Microsoft product, so we can't support non-Microsoft products. I think you can uninstall it directly. If you want, maybe I can provide you with a way to uninstall it.
If you have any ideas about McAffee, you can try to contact the official staff of McAffee, and maybe they can give you a good answer.
I hope the above information is helpful to you. I'm sorry I can't help you in this matter. If you have any questions, please feel free to ask them in the Microsoft community.
Best Wishes
Pyked | Microsoft Community Support Specialist